fix(bookspec): the rebased P7 sentence speaks CHOICE too (P13)

bookspec/spec/rules-index.md

@@ -4,7 +4,7 @@ Every rule of `docs/spec/rules.md` (B-1 to B-45), its bookspec
 identifier `BS-<area>-<n>` (`plan/served.md` P13 step 3), its area,
 what its statement rests on and the examples that demonstrate it.
 
-`docs/spec/rules.md`'s **DECISION** status is bookspec's **CHOICE**:
+A rule whose only source is a human choice carries rules.md's **CHOICE**, bookspec's status of the same name:
 the specification names the options, an engine declares its pick
 (`claims.choices`, `bookspec_checker::Claims`). Rules B-39 to B-45 are
 allocated in `plan/served.md` 8.0.3 and not yet stated: their

docs/spec/rules.md

@@ -1539,7 +1539,7 @@ and a party text field refuses nine digits however they are separated
 (`has_full_tin`: up to three spaces, hyphens, dots, slashes or
 underscores between neighbors, in any script's digits, a run of spaces
 counting once however long it is; and a comma or a parenthesis between
-a TIN's 3-2-4 or 2-7 groups (DECISION, P7, 2026-10-26), so
+a TIN's 3-2-4 or 2-7 groups (CHOICE, P7, 2026-10-26), so
 `123,45,6789` and `(123) 45-6789` read as a TIN while an amount's
 comma-grouped thousands do not, `1,234,567.89` being 1-3-3-2; past ASCII
 every Unicode space and dash and the fullwidth and small forms count, and